ST. LOUIS (KTRS) It’s the end of an era in St. Louis. Monday is Mayor Francis Slay’s last full day in office. To mark the occasion, staffers hung a portrait of Mayor Slay at City Hall during a ceremony Monday afternoon. Slay, who is St. Louis’s longest serving mayor, announced last year his decision not to seek another term. Slay was first elected to the Board of Alderman back in 1985. He later became the president of the Board of Alderman, before he was elected in 2001 to the mayor’s office. He will be succeeded by Mayor-Elect Lyda Krewson, who will be sworn in as St. Louis’s first female mayor Tuesday, April 18.